A generic knee restraint device is known from the European published application EP 0 684 164 A1. The knee restraint device described there has a knee protector plate which is movable by a gas bag towards the knees of a vehicle occupant. The gas bag is able to be filled by a gas source and is arranged between the base and the knee protector plate. Tethers serve both to define an end position of the knee protector plate and to control the movement path of the knee protector plate during the unfolding process. The end position here can lie above the initial position of the knee protector plate. The tethers are arranged inside the gas bag. The gas bag is firmly connected with the knee protector plate and with the base, respectively, by means of securing rings. Due to the tethers being arranged inside the gas bag, the possibilities for their attachment are very limited. Also, an altered end position of the knee protector plate necessitates an altered gas bag construction, because the end position of the knee protector plate is commonly defined by the gas bag wall and the tethers. The fastening of the gas bag to the knee protector plate must be made so as to be pressure-tight and tension-proof and is therefore only able to be realized with difficulty.